Using DHCP on MIVB9

[Tinos]

Hi all.

I always face the below challenge and fail to get it working please assist.
When I enable internal dhcp on MIVB9 and configure option 125, the 53series phones will connect however the 69series especially the 6940 will not come up. The 69series will ask for CloudLink MBG.
What am I missing?

Thank you.

 

[nytalkin]

Are you using NEW phones? Were they USED? If USED, default the phones to factory settings. Try that.

I suppose you're entitled to your opinion, I'm just not going to suppose very hard.

 

[Tinos]

Phones will be new from the box and also same outcome when defaulted.

 

[nytalkin]

I suspect you need a firmware upgrade current release is 69xxFirmware 1.4.0.77

I suppose you're entitled to your opinion, I'm just not going to suppose very hard.

 

[Tinos]

I have noticed that if there are 2 DHCP servers, one being MIVB with option 125 and another DHCP server X, 53series phones will reject offers from DHCP server X and prefer MIVB whereas the 63series will accept DHCP server X ahead of MIVB.

 

[nytalkin]

Sounds odd. Do both DHCP servers reference the same TFTP?

I suppose you're entitled to your opinion, I'm just not going to suppose very hard.

 

[Tinos]

The other third party DHCP server will have no TFTP reference.

 

[meneerB]

On our HP / aruba switches, we had to turn on CDP.
(Altough HP uses LLDP),
otherwise they wouldn't boot.

 

[benny89]

are you doing the voice vlan via OUI? ie MAC Address instead of lldp?
Note some of the 69xx series phones have a different mac address vendor code. Older phones used the 08:00:0f: but some 69xx series phones use 00:08:5d:

 

[Valamagules]

Have you tried Option 43 - Same string as option 125 , make it Global

Clever men learns what Wise men shares!

 

[Tinos]

Just to simplify my scenario. I have a MIVB9 on a table, its DHCP enabled with option 125. I then plug the MIVB9 to a 4 port un-managed switch. I then plug a PC running DHCP service without option 125 or 43 to that switch. I also plug a 5312 and a 6940 to the same switch,
5312 will accept DHCP from MIVB9 because it sees option 125 and disregards the offer from PC. Meanwhile 6940 will accept IP address from PC not see MIVB9. 6940 will attempt to connect to cloud.
Why doesn't 6940 decline DHCP offer that is missing option 125?

 

[Valamagules]

When 69XX comes up with CloudLink MBG usually signifies that it has picked up an IP address however could not locate a Call Server Ip address in the DHCP offer.

I would suggest you do a test -
If you remove the PC DHCP out of the picture, does the 6940 still asks for the ask for CloudLink MBG on MiVB DHCP?
If it does. go into Status settings and verify that you have an IP address, and you will see that Call Server address is blank.
Validate your Option values.




Clever men learns what Wise men shares!

 

[meneerB]

Tinos,
I now understand your question.
Valamagules has a very good point. Does his sugestion work?

From what you tell only proves that the Mitel has a slow DHCP daemon and a 53xx series phone that does something it shouldn't have to do: selecting the better one of the two servers. (Or the 53xx doesn't even accept DHCP offers from the pc!)

What you want is a not supported/ invalid: a DHCP request is a broadcast, each server which is inside that broadcast domain, or each server that has an IP Helper configured on the layer3 switch, will receive the DHCP request.
That said: the client accepts the FIRST offer. bad or good!

I found an old article, but explains the basics.

https://serverfault.com/questions/368512/can-i-have-multiple-dhcp-servers-on-one-network

So, you should always have 2 identical DHCP servers.
Let us know if the 53xx boot when the mitel DHCP is turned off
and if the 69xx boots when the pc is turned off.

 

[jpruder]

My question would be why would one try to run 2 DHCP servers on the same network?

 

[AlphaMann]

I have found that 80% of the time plus the 69XX phones have an issue with option 125.
If all your other settings are correct use option 43 and I bet that will solve the issue.